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FIBRE TO FABRIC (chapter 3)
Wool and silk fibres are obtained from animals.
Wool is obtained from the fleece (hair) of sheep or yak. Silk fibres come from cocoons of the silk moth.
WOOL
Wool comes from sheep, goat, yak and some other animals. These wool-yielding animals bear hair on their body.
Hair trap a lot of air. Air is a poor conductor of heat. So, hair keeps these animals warm.
Wool is derived from
these hairy fibres. , the hairy skin of the sheep
has two types of fibres that form its
fleece:
(i) the coarse beard hair
(ii) the fine soft under-hair close to the
skin.
The fine hair provide the fibres for making wool. Some breeds of sheep possess only fine under-hair.
Their parents are specially chosen to give birth to sheep which have only soft under-hair. This process of selecting parents for obtaining special characters in their offspring, such as soft under hair in sheep, is termed ‘selective breeding’.
ANIMALS THAT YIELD WOOL
Several breeds of sheep are found in different parts of our country
Yak wool is common in Tibet and Ladakh.
Mohair is obtained from angora goats, found in hilly regions such as Jammu and Kashmir.
Wool is also obtained from goat hair.
The under fur of Kashmiri goat is soft. It is woven into fine shawls called Pashmina shawls. The fur (hair) on the body of camels is also used as wool.
Llama and Alpaca, found in South America, also yield wool.
FROM FIBRES TO WOOL
Their hair is cut and processed into wool.
Rearing and breeding of sheep:
In Jammu & Kashmir, Himachal Pradesh, Uttaranchal, Arunachal Pradesh and Sikkim, or the plains of Haryana, Punjab, Rajasthan and Gujarat, We can see shepherds taking their herds of sheep for grazing.
Sheep are herbivores and prefer grass and leaves. Apart from grazing sheep, rearers also feed them on a mixture of pulses, corn, jowar, oil cakes (material left after taking out oil from seeds) and minerals.
In winter, sheep are kept indoors and fed on leaves, grain and dry fodder. Sheep are reared in many parts of our country for wool.
Processing fibres into wool
The wool which is used for knitting sweaters or for weaving shawls is the finished product of a long process,
The following steps:
Step I:
The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing. Machines similar to those used by barbers are used to shave off hair.
Hair are removed during the hot
weather.
This enables sheep to survive
without their protective coat of hair. The
hair provide woollen fibres.
Woollen fibres are then processed to obtain woollen yarn. Shearing does not hurt the sheep just as it does not hurt when you get a hair cut.
Step II:
The sheared skin with hair is thoroughly washed in tanks to remove grease, dust and dirt. This is called scouring.
Step III:
After scouring, sorting is done. The hairy skin is sent to a factory where hair of different textures are separated or sorted.
Step IV:
The small fluffy fibres, called burrs, are picked out from the hair. These are the same burrs which Sometimes appear on your sweaters.The fibres are scoured again and dried. This is the wool ready to be drawn into fibres.
Step V:
The fibres can be dyed in various colours, as the natural fleece of sheep and goats is black, brown or white.Step VI:
The fibres are straightened, combed and rolled into yarn.The longer fibres are made into wool for sweaters and the shorter fibres are spun and woven into woollen cloth.
The processing of fibre into wool can be represented as follows:
Shearing → Scouring → Sorting → Cleaning of burrs → Dyeing → Rolling
SILK
Silk fibres are also animal fibres.
Silkworms spin the ‘silk fibres’.
The rearing of silkworms for obtaining silk is called sericulture.
Life history of silk moth
The female silk moth lays eggs, from which hatch larvae which are called caterpillars or silkworms.
They grow in size and when the caterpillar is ready to enter the next stage of its life history called pupa, it first weaves a net to hold itself.
The caterpillar secretes fibre made of a protein which hardens on exposure to air and becomes silk fibre.
The caterpillar completely covers itself by silk fibres and turns into pupa. This covering is known as cocoon.
Development of the pupa into moth continues inside the cocoon.
Silk fibres are used for weaving silk cloth. The soft silk yarn is as strong as a comparable thread of steel.
The silk yarn (thread) is obtained from the cocoon of the silk moth.
A variety of silk moths which look very different from one another and the silk yarn they yield is different in texture (coarse, smooth, shiny, etc.).
For example- tassar silk, mooga silk, kosa silk, etc., are obtained from cocoons spun by different types of moths.
The most common silk moth is the mulberry silk moth.
The silk fibre from the cocoon of this moth is soft, lustrous and elastic and can be dyed in beautiful colours.
Sericulture or culture of silkworms is a very old occupation in India.
India produces plenty of silk on a commercial scale.
From cocoon to silk For obtaining silk, moths are reared and their cocoons are collected to get silk threads.
Rearing silkworms:
A female silk moth lays hundreds of eggs at a time. The eggs are stored carefully on strips of cloth or paper and sold to silkworm farmers.The farmers keep eggs under hygienic conditions and under suitable conditions of temperature and humidity. The eggs are warmed to a suitable temperature for the larvae to hatch from eggs. This is done when mulberry trees bear a fresh crop of leaves. The larvae, called caterpillars or silkworms, eat day and night and increase enormously in size.
The larvae are kept in clean bamboo trays along with freshly chopped mulberry leaves. After 25 to 30 days, the caterpillars stop eating and move to a tiny chamber of bamboo in the tray to spin cocoons.
Small racks or twigs may be provided in the trays to which cocoons get attached.
The caterpillar or silkworm spins the cocoon inside which develops the silk moth.
Processing silk:
A pile of cocoons is used for obtaining silk fibres.
The cocoons are kept under the sun or boiled or exposed to steam. The silk fibres separate out. The process of taking out threads from the cocoon for use as silk is called reeling the silk. Reeling is done in special machines, which unwind the threads or fibres of silk from the cocoon.
Silk fibres are then spun into silk threads, which are woven into silk cloth by weavers.
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